200

Lens construction:	5 elements in 5 groups
Focus distance:	2 m to infinity
Angle of View:	12° 20'
Aperture scale:	f/4 to f/32
Attachment size:	52 mm
Diaphgram blades:	7 blades
Lens hood:	built-in
Dimensions:	65 mm (diam.) x 124 mm
Weight:	510 g

The 200/4 is quite useful to take pictures of shy animals in the field. Of course you need a close-up lens to attain suitable reproduction ratios, R. With Nikon 3T you can get R values in the 1:3.3-1:2 range at 83-68 cm from the subject. These focusing distances are comparable to those of the Micro-Nikkor 200/4 IF (95-71 cm). With the 4T achromat you'll get 1:1.2 reproduction ratio.

The 200/4 is also quite good at infinity. At full aperture some vignetting is visible, which disappears at f/5.6.

The 200/4 is a great lens for large magnifications (> 1:1) shots. In fact, it works fine when coupled to reversed lenses. In this case, the magnification we can attain is given by 200/X, where X is the focal length (in mm) of the reversed lens. Therefore, if we use a reversed 50 mm, we'll get 200/50 = 4X magnification.

Remember that, when using reversed lenses attached (by stacking rings) to the front of another, the best results are obtained by attaching the longer lens to the camera and reversing the shorter one. In this way, we transform the shorter lens into a highly corrected close-up lens, whose diopters are 1000/X. The 50 mm acts as a highly corrected, multicoated, multielement 20 diopters close-up lens!

Here are some pictures which show how compact the set-up is when a cheap 50 mm f/1.8 E is reversed and attached to the AIS 200/4.

The shooting aperture must be set on the 200 mm lens attached to the camera and the shorter, reversed 50 mm lens is set at its largest aperture, focused at infinity.

The 4X picture below shows the head of a longhorn beetle. Shooting at so high magnifications (> 2X) if often more suited to an indoor studio than to the field. At such magnifications, the vibrations will be drammatically magnified along the subject, even if we use a sturdy tripod. Moreover a careful focusing is mandatory, being the depth of field (DOF) few tenths of millimeter! In the picture below, the estimated DOF, at 4X and f/16, is 0.3 mm!